A Study On The Ecological Efficiency Of Surface-flow Constructed Wetlands In The Old Canal Of Jining City

Wetland refers to the area where the surface is too wet or often accumulated water and wetland organisms grow.Wetlands play an important role in maintaining the earth's water ecology,maintaining the water environment and regulating water resources.Constructed wetland is constructed and controlled by man,which is similar to swamp land.The surface flow constructed wetland is similar to the existing wetland swamp.The water flows through the surface,and there is sediment rich in microorganisms at the bottom.The pollutants in the sewage are enriched in the sediment through natural sedimentation and adsorption.Jining old canal surface flow constructed wetland mainly uses rubber dam,ecological detention pond and surface flow constructed wetland technology to carry out advanced treatment of the old canal intercepted river water,so as to ensure the water quality of the East Route Project of South to north water diversion.After the operation of the project,the actual hydraulic load is far greater than the design load,and the effluent still meets the design requirements of class III surface water,which ensures the stability of Shifo national control section in the west of laoyun River,and plays a good ecological efficiency.In this thesis,the characteristics of the surface flow constructed wetland of the old canal were systematically studied and analyzed:(1)Under the conditions of low pollution load and high hydraulic load,the annual average concentration of main water quality indexes of the surface flow constructed wetland of the old canal: CODMn is 5.04mg/l,NH3-N is 0.303mg/l,TN is 4.48mg/l,TP is 0.092mg/l,and the average removal rates of the corresponding indexes are 23%,7.4%,18% and 51%respectively,which has a good purification effect on the slightly polluted river water.(2)When constructing the surface flow constructed wetland system,the combined process can make up for the shortcomings of each process and realize the optimization of system construction.(3)The old canal surface flow constructed wetland realized the optimization of water retaining facilities,ecological detention pond,surface flow constructed wetland elevation layout,plant configuration,etc.,which reduced the operation cost and enhanced the wetland potential.(4)The construction and operation of the surface flow constructed wetland of the old canal has achieved the goal of stable effluent of the wetland,improved the biodiversity in the region,and achieved remarkable results in water purification and ecological restoration.(5)The old canal surface flow constructed wetland can reduce CODMn 165 tons,ammonia nitrogen 8.28 tons,total phosphorus 9.17 tons and total nitrogen 83.79 tons every year,which has obvious environmental benefits and certain economic benefits.This paper systematically studies the actual effect of the old canal surface flow constructed wetland in the treatment of micro polluted river water,which has a certain degree of reference significance for the purification of micro polluted river water through the application of surface flow constructed wetland technology in the future.